Which PFPS subtype is defined by excessive knee valgus during dynamic tasks?

• A. Muscle power deficit
• B. Mobility impairment
• C. Movement coordination deficit
• D. Overuse/overload PFPS

Answer: (C)

Excessive knee valgus during dynamic tasks reflects a breakdown in neuromuscular coordination of the lower limb. When performing movements like squats, landings, or cutting, the knee should track in line with the foot with proper timing of hip, thigh, and trunk muscles. If hip abductors and external rotators, along with core and trunk stabilizers, don’t activate in the right sequence, the knee collapses inward into valgus. This altered movement pattern increases patellofemoral joint stress and is a hallmark of the movement coordination deficit subtype in PFPS.

The other patterns don’t capture this dynamic control issue as clearly. A muscle power deficit focuses on reduced strength rather than the specific, timing-based maltracking. A mobility impairment points to restricted joint range that limits motion, not necessarily a faulty coordination pattern during task performance. An overuse/overload pattern centers on repetitive stress from training volume or technique, rather than the distinctive neuromuscular control of dynamic knee alignment.